'tmpdir' required to execute Rakefile

Causes error in Rails https://travis-ci.org/rails/rails/jobs/40567972

rake aborted!
NoMethodError: undefined method `mktmpdir' for Dir:Class
/home/travis/build/rails/rails/vendor/bundle/jruby/1.9/bundler/gems/activerecord-jdbc-adapter-9a35519775e7/Rakefile:168:in `(root)'